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{"bugzilla": {"description": "firefox: Mitigation bypass in the DOM: Security component", "id": "2428969", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2428969"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2026-0877", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "rhel10/firefox-flatpak", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "firefox", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-01-13T13:30:52Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-0877\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-0877\nhttps://www.mozilla.org/security/advisories/mfsa2026-03/#CVE-2026-0877"], "statement": "Red Hat Product Security rates the severity of this flaw as determined by the Mozilla Foundation Security Advisory.", "threat_severity": "Important"}

{"analysis": {"en": {"generated_at": "2026-04-15T21:51:20.703187+00:00", "value": {"mitigation_remediation": ["Upgrade Firefox to version 147 or ESR 115.32/140.7 and Thunderbird to version 147 or ESR 140.7 or later", "If an upgrade is not possible, uninstall or disable older Firefox or Thunderbird installations to prevent execution of vulnerable software", "Apply the latest security patches as listed in Mozilla release notes and monitor advisories for any additional mitigation steps"], "summary": {"action": "Immediate Patch", "impact": "Browser DOM security component bypass"}, "threat_synthesis": {"affected_systems": "All Mozilla Firefox releases below version 147, all ESR builds before 115.32 and 140.7, and all Mozilla Thunderbird releases below version 147 or ESR builds below 140.7 are vulnerable. Versions 147 and later, ESR 115.32 or 140.7 and later are secure.", "description_and_impact": "Firefox and Thunderbird contain a flaw that can bypass built\u2011in DOM security checks. The effect is that a malicious script could run in the browser context. Based on the description, it is inferred that this could enable theft of user data, credential compromise, or further malicious activity, although the official CVE text does not explicitly state these outcomes.\nThe vulnerability was fixed in Firefox 147, Firefox ESR 115.32, 140.7, Thunderbird 147, and Thunderbird 140.7.", "risk_and_exploitability": "The CVSS score is 8.1, indicating high severity, while the EPSS score is <1%, showing a very low exploitation probability. It is not listed in the CISA KEV catalog. Based on the description, it is inferred that the attack vector is a malicious web page or email containing crafted content that targets the DOM security component; exploitation would require user interaction such as visiting the page or opening the message."}}}}, "created": "2026-01-14T11:09:24.156662+00:00", "updated": "2026-04-15T22:00:06.628340+00:00", "vendors": ["mozilla", "mozilla$PRODUCT$firefox", "mozilla$PRODUCT$firefox_esr"]}